B. Role in the MHCRC and Specific Aims - It is hypothesized that structural and metabolic factors in the brain play an important role in the pathogenesis, course and outcome of psychotic disorders including schizophrenia, schizoaffective disorders, manic depressive and major depressive disorders with psychotic symptoms, and major depressive disorders. Neuroimaging methods can be used to test this hypothesis. Moreover, MR approaches can be used as measures of treatment effect (both therapeutic and adverse), and thus may be useful in new drug discovery, as well as in the evaluation of efficacy and toxicity. The overall goals of the Neuroimaging Core are: 1. To provide MHCRC investigators state-of-the-art methods for neuroimaging using MRI, MRS and fMRI that are validated and reliable for the study of selected mental disorders. 2. To provide technical assistance and scientific collaboration to MHCRC investigators in the development of neuroimaging protocols, data analysis, and interpretation. 3. To develop and implement new methods in MRI, MRS and fMRI that advance the field of neuroimaging and make these available to MHCRC investigators. 4. To provide a scientific environment that encourages the application of neuroimaging methods to the study of selected mental and behavioral disorders and provides an infrastructure for training in neuroimaging research. The primary aims of the Neuroimaging Core of the MHCRC are to investigate the neurobiology of mental disorders, assess the effects of treatment, and test specific hypotheses of MHCRC investigators. This involves cross- sectional comparisons of selected patient samples and matched control groups, longitudinal repeated measures of selected patients and control samples, assessment of patients with MR applications in the context of previously developed and validated paradigms (cognitive, behavioral and pharmacologic) and pre and post treatment assessments.